Feeding devices for liquids



Feb. l5, 1966 J. B. FULLMAN 3,235,136

FEEDING DEVICES FOR LIQUIDS JAMES B. FULLMAN Feb. 15, 1966 .1.5. FULLMAN FEEDING DEVICES FOR LIQUIDS 2 Sheets-Sheet 2 Filed Feb. 20, 1964 Il IO FIG.3

FIG

INVENTOR JAMES B. FULLMAN FIG-5 United States Patent 3,235,136 FEEDING DEVICES FOR LIQUIDS James B. Fullman, Stamford, Conn., assignor to Water Service Laboratories Inc., New York, N.Y., a corporation of New York Filed Feb. 20, 1964, Ser. No. 346,265 2 Claims. (Cl. 222-250) This invention relates to feeding devices for liquids such as chemical solutions used in the treatment of water, and has for its main object the provision of a device which is simple in construction and economical in manufacture, yet accurate, consistent and reliable in performance. Another object is the provisionof'a feeding device which maintains a high degree of accuracy and consistency even under varying operating conditions. Still another object is the provision of means for Varying the rate of feeding to meet changing requirements.

The manner in which these objects are achieved will become apparent from the following description and from the accompanying drawings, in which:

FIG. 1 is a view, partly in section, of a feeding device in accordance with my invention;

FIGS. 2 and 3 are views, similar to FIG. l, of modilied forms of myinvention; and

FIGS. 4 and 5 are views, on an enlarged scale, of the two faces of one of the intermediate plates of the feeding devices shown in FIGS. l to 3.

Like reference characters refer to like parts throughout the several views.

Referring now to FIG. 1, a feeding device in accordance with my invention comprises a diaphragm made of soft and exible material of the nature of natural or vsynthetic soft rubber. The type of material commercially available in sheet form with a fabric re-inforcement ernbedded therein is particularly well adapted to use as diaphragm. On either side of the diaphragm 10 is an intermediate plate 11 and 21, respectively. As shown more clearly in the enlarged views of FIGS. 4 and 5, the plate 11 has `a flat face 12 (juxtaposed to the diaphragm 10) provided with a cavity 13. The opposite face 14 is likewise flat and provided with an underdrain 15 comprising a plurality of concentric circular channels 16 and radial channels 17 interconnecting the circular channels 16, all being open into the face 14. Scattered over the entire surface of cavity 13 is a multiplicity of relatively small ports 18 communicating with the underdrain 15. Be-

tween the various channels 16 and 17 are land areas 19 in the plane of face 14. `The plate 11 is preferably square,

`as shown, and has in each of its four corners a bolt hole ,20.

The intermediate plates 11 and 21 are advantageously made of hard rubberor other sufiiciently rigid and suitable plastic material, but they may also be made of metal. The plates 11 and 21 are alike in the interest of economy and convenience. Thus, plate 21 has a cavity 23 facing the diaphragm 10, an underdrain 25 on its opposite face,

:and a multiplicity of relatively small ports 28 scattered having the underdrain 25 therein.` The plate 35 has apassage 36 therethrough communicating with the top porp tion of `underdrain 25, and another passage 37 closed by a plug 3S and communicating with the bottom porti-on of underdrain 25; The end plates 30 and 35 are also alike for convenience and economy in manufacture.

3,235,136 Patented Feb. .15, 1966 lCe The diaphragm 10, intermediate plates 11 and 21, and en-d plates 3i) and 35 all have matching bolt holes, as indicated at 20 in FIGS. 4 and 5, and are held together by bolts (not shown). This assembly constitutes a diaphragm pump which is controlled by the similar solenoid valves 40 and 41. They are of the so-called three-way type, such as shown in U.S. Patent 2,614,584, dated October 21, 1952, each having a normally open connection NO, anormally closed connection NC and a common `connection C, When the solenoid valves are de-energized there is -communication between connections NO and C, and connection NC is closed. When the solenoid valves are energized there is communication between connections NC and C, and connection NO is closed. The solenoid valves 40 and 41 are connected in parallel by wiring 42 to a time switch 43 which in turn is connected by wires 44 to a source of electric energy. The time switch 43 is thus adapted to control the operation of the two solenoid valves 40 and 41, alternately energizing and deenergizing both of them in unison.

A tank 45 is provided to contain a supply of chemical solution or other liquid to be fed. The tank 45 has an outlet pipe 46 leading to a strainer 47 provided to retain solid particles which might become lodged in the relatively small passages of the solenoid valves and interfere with their proper functioning. As shown in FIG. l the solenoid valve 40 has its common connection C in communication with passage 31 by a pipe 48, its normally open connection NO in communi-cation with strainer 47 by a pipe 49, and its normally closed connection NC in communication by a pipe 50 with a point of disposal or use for the liquid fed from tank 45. The solenoid valve 41 has its common connection C in communication with passage 36 by a pipe 51 and its normally closed connection NC in communi-cation with a pipe 52 leading to a suitable source of motivating fluid under pressure which may be a liquid, such as water, or a gas, as for instance, air. The normally open connection NO of the solenoid valve 41 leads through a pipe 53 to a point of disposal which may be a sewer or drain when the motivating fluid is water, or the atmosphere when the motivating fluid is a gas, or a point of use when it is desired to utilize the motivating fluid.

FIG. l shows the feeding device with the diaphragm 10 in the position in which it is at rest after the solenoid valves 40 and 41 have been energized. Motivating fluid has entered through pipe 52, connections NC and C of solenoid valve 41, pipe 51. passage 36, underdrain 25 and ports 28 into cavity 23 and pushed the diaphragm 1t) snugly against the surface of cavity 13, as shown. After an interval of time determined by the time switch 43 both solenoid valves 40 and 41 are de-energized, establishing communication between connections NO and C, and closing the connections NC. Now liquid from tank 45 flows via pipe 46, strainer 47, pipe 49, connections NO and C of solenoid valve 40, pipe 48, passage 31, underdrain 15,` and ports 18 into cavity 13. As cavity 13 iills with liquid from tank 45 the diaphragm 10 is pushed to the right until it rests snugly against the surface of cavity 23 (the position shown in FIG. 2) while the motivating fluid previously occupying the space in cavity 23 to the right of diaphragm 10 is being forced via ports 2S, underdrain 25, passage 36, pipe 51, connections C and NO of solenoid valve 41 and pipe 53 to a point of disposal. After a further interval of time, again determined by the time switch 43, both solenoid valves 40 and 41 are again energized, establishing communication between connections NC and C, and closing the connections NO. Now motivating fluid entering into pipe 52 flows via connections NC and C of solenoid valve 41, pipe 51, passage 36, underdrain 25 and ports 28 into cavity 23. As cavity 23 fills `with motivating 'fluid the diaphragm liti is pushed to the l'eftuntil' it`rests'snugly'against the surface of cavity 13 (the position shown in FIG. l) while the liquid previously occupying the space in cavity 13 to the left of diaphragm has been forcedvia ports 18, underdrain 15, passage 31, pipe 43, 'connections C and NC of solenoid valve 40 and through pipe 50 to a point of use.

The diaphragm itl is initially flat, but since during use it is alternately forced against the surfaces of cavities '13 and 23 it soon becomes permanently deformed by acquiring a bulge in its central portion, Thereafter it offers vlittle resistance to movement from one position to the other. Consequently, only a relatively small pressure differential is needed for operation of the feeding device. The land 'areas of the intermediate plates 11 and 21, as shown at y19 in FIG. 5,v rest against the end plates 30 and 35, respectively, and thus form 'supports which prevent any distortion of the `cavities 13 and 23, respectively, which might otherwise occur, 'especially at high pressure differentials, and which would adversely affect the accuracy and consistency of the feeding device.

The distribution or scattering of the ports 18 and 28 over the entire surfaces of cavities 13 and 23, respectively, as shown in FIG. 4, is most important. If only a single port were provided in each cavity, or even several ports near each other, the diaphragm would reach and close such ports before the cavities have been drained completely, thereby trapping variable quantities of liquid or iluid and causing inaccuracies and inconsistencies in the voiume of liquid or fluid discharged during successive energizations. The communication of passage 31 with the top portion of underdrain is also important because in this manner any air or gas which may have entered with the liquid being fed is immediately discharged with the outflowing liquid and thus cannot accumulate. The retention of any such gas or air, because of its substantial compressibility, would cause inaccuracies and inconsistencies in the rate of feed. The screw plugs 33 and 38 are provided to permit periodic removal of sludge and other settled matter from the bottom portion of underdrains 15 and 25, respectively.

For satisfactory functioning it is necessary that the pressure of the motivating iiuid supplied to pipe 52 is higher than the pressure existing at the point of use with which pipe 50 'is connected, and that the pressure or head of liquid supplied to pipe 49 is higher than the point of disposal with which pipe 53 is connected. The latter condition is usually metal in a satisfactory manner if the minimum level of liquid in tank 45 is located at least one foot above the pipe 51 and above the point of disposal with which pipe 53 is connected.

A feeding device constructed and operated as described will discharge accurately through pipe 50 to the point of use, on each energization of the solenoid valves 4t) and 41, a volume of liquid which is Vequal to the sum of the volumes of cavities 13 and 23. This discharge is maintained consistently even with relatively large variations in the pressure of motivating fluid supplied to pipe 52, and in the head of liquid in tank 45. The head of liquid in tank 45, of course, decreases gradually as liquid is being fed out, and increases abruptly when the tank is periodic'ally refilled with liquid. Since the feeding device disl charges a fixed volume of liquid on each energization of the solenoid valves 40 and 41 the quantity of liquid fed per unit of time may readily be changed or adjusted by changing the time interval between successive energizations, and this may be accomplished if the time switch 43 is of a type, commercially available, in which the number of energizations per unit of time may be varied. The duration of each energization and de-energization may be as long as desired, provided it is suiiioient to permit complete emptying and filling of the cavities 13 and 23 for which a minimum time of about l0 to l5 seconds is adequate under ordinary conditions.

It is to be noted that if the motivating flu-id is a liquid then during each ope-rating"cycle"consisting of one energization and on de-energization of the solenoid valves 40 and 41 the volume of motivating fluid discharged through pipe 53 is equal to the volume of liquid originating from tank 45 and discharged through pipe 50. In View of this fact it 'is possible to employ a single feeding device when equal quantities of `two different liquids are to be fed per unit of time, by providing for the second liquid 'another tank, similar to tank 45, and rconnecting it to pipe 52 in lieu of some other'source of motivating uid. The two liquids being fed out through 'pipes 50 and 53 may be sent 'to different points of use or combined in a single point of use, as desired, but'such 'point or points of use must be at an elevation lower than vthe levels of liquid in the two tanks.

FIG. -2'shows'a1special arrangement in which a single liquid is being fed withoutrequiring any other motivating iiuid. In this modication the strainer 47 is connected by a pipe 55 with a T '56 which in turn is connected by a pipe 57 with the connection NO of solenoid valve 40, and by a pipe '58 with the connection NC of'solenoid valve 41. The diaphragm 10 is shown in FIG. 2 in the position it occupies when both solenoid valves 40 and 41 are deenergized.

Operation of the device shown in FIG. 2 is as follows. On energization of the solenoid valves 40 and 41 liquid from tank 45 flows via pipe 46, strainer 47, pipe 55, T 56, pipe 58, connections NC and C of solenoid valve 41, pipe 51, underdrain 25 and ports 28 into cavity 23, vpushing the diaphragm 10 to the left and yforcing the liquid from cavity 13 via ports 18, underdrain 15, pipe 48, connections C and NC of solenoid valve 40, and pipe 56 to a point of use. When the solenoid valves 40 and 41 are again deenergized by the time switch 43, liquid from tank 45 ows via pipe 46, strainer 47, pipe 55, T 56, pipe 57, connections NO and C of solenoid valve 4), pipe 48, underdrain 15 and ports 18 into cavity 13, pushing the diaphragm 10 to the right and forcing the liquid from cavity 23 via ports 28, underdrain 25, pipe 51, connections C and vNO of solenoid valve 41, and Vpipe 53 to a point of use. This completes a'n operating `cycle and restores thc device to the position shown in FIG, 2. The volumes of liquid discharged through pipes '50 and 53 per operating cycle are equal, and they may be passed to two different points of use or combined at a single point of use, as desired.

FIG. 3 shows a modification of `a feeding device according to my invention in which in addition to or in lieu of the 'adjus'tability of time switch 43 means are provided to permit a stepless adjustment of the rate of feeding. In this arrangement there are a second diaphragm 60 and a fiat spacer 61 between the diaphragm It) and the intermediate plate 21. The spacer 61 has a space 62 in its central portion open towards and bounded by diaphragms 10 and 60, and in communication with a passage 63 closed by a plug 64, as well as with a tube 65 connected with a cylinder 66. Axially movable in the cylinder 66 through a stuiiing box 67 is a piston 68 by means of a screw 69 fitted into a threaded hole 70 in piston 68. A tail piece 71 of screw 69 is rotatable in a hole 72 in a yoke 73. A handle 74, fastened to the tail piece 71 by 'a pin 75, prevents axial shifting of the screw 69 but permits rotation thereof for the purpose of changing the position of piston 68 in cylinder 66. The space 62 between the diaphragms 10 and 69, as well as the tube 65 and the cylinder 66 are lled with an essentially incompressible buffer liquid 76, such as oil, or water. The plug 64 is provided to permit introduction of the buffer liquid 76 and removal of air.

In FIG. 3 the diaphragms 10 and y6'() are shown in a position which they may occupy with the Solenoid valves 40 and 41 de-energized, these valves being connected as shown in either FIG. 1 or FIG. 2. While the diaphragm 60 rests against the lsurface of cavity 23, the diaphragm 10 is substantially at, and the volume of liquid in cavity 13 and bounded by diaphragm 10 is equal to the volume of the cavity 13. This is the volume of liquid which will be discharged through pipe 50 upon subsequent energization of the solenoid valves 40 and 41. It is halt` the volume which is discharged in FIGS. 1 or 2 wherein the discharge on each energization equals the sum of the volumes of cavities 13 and 23. It is to be noted that in FIG. 3 the piston 68 is about half-way in the cylinder 66. If the piston 68 is now moved further into cylinder 66 by rotating the handle 74 the volume of buffer liquid 76 in the open space 62 bounded by the diaphragme 10 and 60 will be increased and the diaphragm will be pushed to the left until it finally rests in contact with the surface of cavity 13, just as diaphragm 60 is in contact with the surface of cavity 23. Now both diaphragms 10 and 60 are locked in place and unable to move when the solenoid Valves 40 and 41 are alternately energized and de-energized. In other words, the rate of feeding then is zero. As the piston 68 is now moved out of cylinder 66 the volume of buffer liquid 76 in the space 62 between the diaphragrns 10 and 60 is gradually decreased, and the rate of feeding is increased correspondingly. Thus, there is provided a stepless adjustment in the rate of feeding from zero to the maximum capacity of the feeding device. Means other than piston 68 and cylinder 66, for example, bellows, may be used to vary the volume of buffer liquid 76 in the space 62 between the diaphragms 10 and 60.

When it is desired to feed two different liquids at different rates the devices of FIGS. 1 and 3 may, for instance be combined. In that event a single solenoid valve 41 may be used to control the ow of motivating Huid to and from both devices, and a single time switch 43 to control all of the solenoid valves.

Modifications other than those specifically mentioned herein may be made without departing from the spirit of this invention, and reference is, therefore made to the following claims for a denition of the scope of my invention.

What I claim is:

1. A feeding device for liquid comprising a diaphragm made of soft and flexible material, two intermediate plates each having two opposite flat faces, one of said faces being adjacent to one side of said diaphragm and having a cavity therein and the other of said faces having a system of open interconnecting channels therein forming an open underdrain, each of said intermediate plates also having a multiplicity of ports scattered over the surface of its said cavity and communicating with its said underdrain, a pair of end plates each having a flat surface juxtaposed to the llat face of one of said intermediate plates having said underdrain therein., and thereby enclosing said underdrain, a passage in each of said end plates terminating in its said surface and communicating with one of said underdrains, a pair of threeway solenoid valves, each having a normally open port adapted to be closed on energization of the solenoid valve, a normally closed port adapted to be opened on energization of the solenoid valve and a common port in. communicai tion with both said normally open port and said normally closed port, each of said solenoid valves having its common port connected with the said passage in one of said end plates, one of said solenoid valves having its normally open port connected with a source of liquid under pressure and its normally closed port connected with a point of disposal, the other of said solenoid valves having its normally closed port connected with a source of fluid under pressure and its normally open port connected with a point of disposal, and a time-switch connected with said solenoid valves and adapted to alternately energize and de-energize both said solenoid valves in unison.

2. The feeding device of claim 1, the saidunderdrain in at least one of said intermediate plates consisting of a system of circular and radial channels, and land areas between said channels.

References Cited by the Examiner UNITED STATES PATENTS 2,795,359 6/1957 Lehman 222-249 2,881,596 4/1959 Sheen 222-250 X FOREIGN PATENTS 403,465 9/ 1924 Germany. 414,035 5/ 19125 Germany.

LOUIS I. DEMBO, Primary Examiner.

HADD S. LANE, Examiner. 

1. A FEEDING DEVICE FOR LIQUID COMPRISING A DIAPHRAGM MADE OF SOFT AND FLEXIBLE MATERIAL, TWO INTERMEDIATE PLATES EACH HAVING TWO OPPOSITE FLAT FACES, ONE OF SAID FACES BEING ADJACENT TO ONE SIDE OF SAID DIAPHRAGM AND HAVING A CAVITY THEREIN AND THE OTHER OF SAID FACES HAVING A SYSTEM OF OPEN INTERCONNECTING CHANNELS THEREIN FORMING AN OPEN UNDERDRAIN, EACH OF SAID INTERMEDIATE PLATES ALSO HAVING A MULTIPLICITY OF PORTS SCATTERED OVER THE SURFACE OF ITS SAID CAVITY AND COMMUNICATING WITH ITS SAID UNDERDRAIN, A PAIR OF END PLATES EACH HAVING A FLAT SURFACE JUXTAPOSED TO THE FLAT FACE OF ONE OF SAID INTERMEDIATE PLATES HAVING SAID UNDERDRAIN THEREIN, AND THEREBY ENCLOSING SAID UNDERDRAIN, A PASSAGE IN EACH OF SAID END PLATES TERMINATING IN ITS SAID SURFACE AND COMMUNICATING WITH ONE OF SAID UNDERDRAINS, A PAIR OF THREE-WAY SOLENOID VALVES, EACH HAVING A NORMALLY OPEN PORT ADAPTED TO BE CLOSED ON ENERGIZATION OF THE SOLENOID VALVE, A NORMALLY CLOSED PORT ADAPTED TO BE OPENED ON ENERGIZATION OF THE SOLENOID VALVE AND A COMMON PORT IN COMMUNICATION WITH BOTH SAID NORMALLY OPEN PORT AND SAID NORMALLY CLOSED PORT, EACH OF SAID SOLENOID VALVES HAVING ITS COMMON PORT CONNECTED WITH THE SAID PASSAGE IN ONE OF SAID 